The application of labels to articles and products has been and continues to be an important step in providing product identification, specific product information and marketing advantages. Manufacturers of various products are continually seeking a more efficient and effective manner in which to apply labels to articles or items, such as cartons, containers or any other packages or products having a surface capable of securely receiving an adhesive label.
Numerous methods have been employed in the past to mark articles, such as color-coded ink sprays and manually applied stickers. The introduction of adhesive-backed pressure sensitive labels and hand-held, manually operated applicators has greatly facilitated the marking of articles in that the applicators provide a simple means for applying an adhesive-backed label to an article. Such hand-held label applicators are well known and used extensively in various industries, for example, for marking the price of articles to be sold. Their use, however, in manufacturing, assembling and distributing applications is limited because of the necessity for marking many items at a high rate of speed. In these applications, the articles to be labeled are transported along a conveyor past a number of stations, one of which often entails the application of a label to each article as it passes by or while the conveyor is stopped. Use of a hand-held label applicator in this type of high speed operation would be unacceptably slow, inefficient, labor intensive and therefore, impractical due to the time constraints associated with high volume production.
As a result, relatively high speed labeling machines have been developed to apply labels to articles advancing by a labeling station on, for example, a conveyor belt. The pressure-sensitive labels are commonly precut and carded on a continuous web of material often called backing material which is rolled into a roll for mounting on the labeling machine. The backing material is somewhat more flexible than the label itself. This allows the label to be separated from the backing material simply by bending the backing material sharply away from the label, which is usually done by a drawing the backing over an fairly sharp stripping or peeling edge of a peeling bar or plate. The less flexible label then separates from the backing material and remains relatively straight for application to the article by some type of applicator. For example, U.S. Pat. Nos. 3,984,277 to French et al. and 3,806,395 to French disclose label machines for positioning by a conveyor belt which use a vacuum-blow type applicator having a label receiving surface with openings formed therein. A vacuum-blow control valve is used to create a vacuum on the receiving surface of the applicator causing the label dispensed from the peeler bar to be held against the receiving surface by vacuum pressure. Once an article is moved into position below the label, the vacuum-blow air valve operates to provide a blast of air through the openings thereby blowing the label onto the article. However, these labeling machines do not permit the applying position of the label on the package to be easily varied. In order to change the applying position of the label relative to the article, these machines require repositioning of the article on the conveyor belt relative to the labeling machine and/or manually repositioning the entire labeling machine. Moreover, there are many instances in which it is desirable, more efficient, or simply necessary to label articles arranged in a side by side relationship on a conveyor transverse to the feed path of the articles. For example, some assembly or manufacturing stations upstream of the labeling station discharge articles in a side by side arrangement across the conveyor. However, the machines disclosed in French '395 and French et al. '277 must receive articles conveyed in a single row along the feed path on the conveyor to allow the applicator to apply the label to each article and, therefore, these machines are incapable of quickly and effectively labeling a transverse row of articles.
Another type of labeling machine includes the use of a movable applicator assembly for acquiring a label from a peeler bar, moving transversely across the conveyor away from the peeler bar and applying the label to the article. Various embodiments of this type of labeling machine are disclosed in U.S. Pat. Nos. 4,191,607 to Cope, 4,595,447 to Lindstrom, 4,612,079 to Ostrow and 4,822,442 to Ashcraft et at. Since the applicator assembly of these machines may be moved away from the peeler bar to a variety of locations transverse to the conveyor while carrying the dispensed label, these machines do not depend entirely on the position of the article for accurate placement of the label. However, it has been found that during movement of the applicator assembly from the dispensing position, in which a label is dispensed onto the receiving surface of the applicator, to the applying position adjacent the article, the label often inadvertently moves relative to the receiving surface due to machine vibration, abrupt movements and inertial and wind forces acting on the label. This inadvertent movement of the label during movement of the applicator assembly is even more probable in high speed operations and results in unpredictable positioning and orientation of the label on the article. Consequently, the location and orientation of the label on the article may be undesirable and even unacceptable. Moreover, these types of machines require the applicator assembly to move through a delivery stroke from the peeler bar and a return stroke back to the peeler bar for each dispensed label thereby expending a significant amount of operating time for each label. This unnecessarily large amount of operating time per label makes it more difficult to obtain the high speed labeling desired in present applications.
U.S. Pat. No. 4,046,613 to Kucheck et al. discloses a labeling machine having a label applicator capable of applying labels to articles arranged in a side by side arrangement across a conveyor. This machine uses a revolving belt having a vacuum-blow type receiving surface positioned across the article conveyor belt for receiving the labels in sequence from a peeler bar positioned adjacent the article conveyor belt and then applying the labels to respective articles. The machine also includes a fine positioning means including various retractable pins operated by individual air cylinders which act as stops for respective labels positioned on the receiving surface. However, since the labels are moved through a relatively large distance after being dispensed from the backing material by the peeler bar located adjacent the article conveyor belt, a significant opportunity for inadvertent movement of the label on the belt exists even with the use of the vacuum surface. Moreover, the fine positioning means is undesirably complex and appears to require inconvenient manual adjustment when the position of the article is changed in order to maintain this fine positioning control. In addition, this machine does not provide for automatic longitudinal movement of the applicator assembly along the feed path of the articles during operation of the labeling machine as may be desirable in order to label an array of articles positioned on a conveyor.
U.S. Pat. No. 5,133,827 to Ratermann discloses a labeling machine wherein the dispensing means (peeler bar) and applicator means are mounted with the supply roll of labels on an arm overhanging the conveyor. This design allows the whole overhanging assembly to be moved transversely to position the dispensing means immediately adjacent each article, thus avoiding the disadvantages of carrying a dispensed label a relatively large distance to the article. However, this design does not appear to permit labeling of articles positioned in a side by side arrangement across the conveyor since the applicator means relies on the movement of the article to assist in applying the label and only one label may be applied at a time. Moreover, a large number of components, such as the supply roll, the driver roll and associated motor for pulling the web of labels from the roll, and various idler rollers are all mounted on the movable labeling assembly which transverses the conveyor. As a result, the movable labeling assembly is much heavier than necessary, requiring a stronger, more durable support structure. Also, the large weight of the movable labeling assembly creates high inertia requiring more powerful operating components while making high speed operations more difficult.
U.S. Pat. No. 4,518,450 to Warmann discloses an automatic labeling machine including a dispensing assembly movably positioned over the conveyor for applying the label to an article. However, the movable dispensing assembly includes the supply of labels and is, therefore, large and heavy. Moreover, this machine moves the label a substantial distance after it has been dispensed from the backing material, and, therefore, does not solve the problems of the prior art as discussed hereinabove.
U.S. Pat. No. 4,624,734 discloses a labeling machine which separates the dispensing station from the supply station using a guide leg extending from a stationary supply station including a supply roll positioned adjacent the conveyor. An articulated dispensing head connected to the outer end of the guide leg, a spaced distance from the supply station, dispenses a label from a continuous web of labeling material fed to the dispensing head from the supply roll. The empty backing strip then travels back to a waste roll mounted at the supply station. This arrangement permits the installation of the dispensing head into a confined region on the packaging line. However, this machine is not capable of labeling articles arranged in a side by side manner across the conveyor since the guide arm and articulated head do not move transversely.